1. Field of the Invention
The present invention relates to a power converting apparatus.
2. Discussion of the Background
Power converters generally include a plurality of heat generators in air ducts, and the heat generators are cooled with cooling air. In applications where the plurality of heat generators are arranged in series in the upwind-downwind direction, the cooling air increases in temperature through heat exchange with the upwind heat generators and flows as such to the downwind heat generators. This results in a difference in the amount of heat radiation between the upwind and downwind heat generators.
In view of this, Japanese Unexamined Patent Application Publication No. 2004-186702 discloses a power converting apparatus including an air duct with a decremental cooling-air flow channel in the upwind-downwind direction. Specifically, the power converting apparatus includes a plurality of heat generators (heat radiating fins) arranged in series in the air duct. The cooling-air flow channel (serving a passage of air) in the air duct is decremental in the upwind-downwind direction. This increases the flow rate of the cooling air, and allegedly improves the cooling efficiency of the downwind heat generators and allegedly uniformizes the amount of heat radiation between the upwind and downwind heat generators.